Diverse experimental techniques were used for the determination of acetaminophen (N-(p-Hydroxyphenyl)acetamide, N-acetyl-p-aminophenol) in aqueous and non-aqueous media. A study was performed on the electrochemical characterization of acetaminophen at a noble-metal electrode. A pretreatment procedure on the gold electrode was developed under basic conditions. The anodic peak current was the analytical parameter used. Spectrometric techniques were used as detection means, and their analytical potential was evaluated. Infrared techniques such as transmission and attenuated total internal reflection (ATR) were used for the quantitative determination of acetaminophen. The molar absorptivity of acetaminophen was calculated at the carbonyl infrared band from the calibration data obtained from the experiments performed in non-aqueous solvents using the transmission technique. The attenuated total internal reflection technique was used to overcome limitations on the use of the infrared transmission technique for aqueous based systems. A quantitative study was undertaken of the possibilities for the determination of acetaminophen in aqueous solutions by coupling flow injection analysis (FIA) with Fourier transform-infrared (FT-IR) spectrometry. Optimization of the basic flow injection FT-IR system was performed. The cylindrical internal reflection cell for liquid evaluation (CIRCLE$\sp\circler$) was used as the detector cell compatible with aqueous solutions. Applications to systems involving on-line chemical reactions by coupling the flow injection analysis technique with infrared spectrometric detection were described. Flow injection spectrophotometric and infrared detection methods were developed for the determination of acetaminophen based on its hydrolysis reaction with sodium hydroxide to form p-aminophenol and its oxidation with potassium ferricyanide to produce an orange-red species, p-benzoquinonemonoimine. The developed methods were evaluated by analysis of tablets of a commercial formulation. The ability of flow injection techniques for generating transient product profiles combined with the infrared mode for monitoring reaction species was investigated to help in the study of reaction mechanisms. Ab initio calculations were performed on acetaminophen at the 3-21G level of the theory. Structural parameters were optimized for the two conformations of acetaminophen. The calculated and experimental spectra were compared in terms of the infrared vibrational frequencies.
| Identifer | oai:union.ndltd.org:UMASS/oai:scholarworks.umass.edu:dissertations-9085 |
| Date | 01 January 1995 |
| Creators | Ramos-Fontan, Maiella L |
| Publisher | ScholarWorks@UMass Amherst |
| Source Sets | University of Massachusetts, Amherst |
| Language | English |
| Detected Language | English |
| Type | text |
| Source | Doctoral Dissertations Available from Proquest |
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